【作者】 叶成志； 刘志雄； 黄小玉； 周雨华；

【Author】 Ye Chengzhi1 Liu Zhixiong2 Huang xiaoyu1 Zhou yuhua1 (1. Hunan Meteorological Office,Changsha 410007; 2. Loudi Meteorological Office, Loudi 418000)

【机构】 湖南省气象台； 娄底市气象台；

【摘要】 本文利用常规、地面加密观测资料和常德多普勒雷达资料,结合MM5V3中尺度数值模式模拟结果对“03.7”湘西北特大致洪暴雨过程进行了综合分析,结果表明:“03.7”湘西北特大暴雨与边界层内多个中尺度辐合扰动的移动和发展相伴,边界层的中尺度辐合扰动诱发了中β尺度涡旋,且伴随着中尺度雨团的强烈发展,构成了特大暴雨的直接影响系统;在暴雨发生区对流层中低层呈现出明显的重力波列等快波特征,同时垂直速度分布也表现为上升运动和下沉运动相间的波动特点,重力惯性波可能是此次特大暴雨的触发机制;等熵面上的位涡下滑和倾斜涡度的发展是导致中β尺度气旋涡度急剧发展的主要因素;湘西北特殊地形对此次暴雨过程有明显的触发和增幅作用。更多还原

【Abstract】 Based on the conventional or dense observational meteorological data and Changde Doppler radar data, combining with simulation output of high-resolution MM5V3 Model, the heavy rainfall which resulted in severe floods in the Northwest of Hunan province was analyzed. The result shows the heavy rainfall process was accompanied with motions and developments of several mesoscale convergent disturbances in the boundary layer. Such disturbances on the convergence line in the boundary layer induced a meso-?-scale vortex disturbances and the rapid development of a mesoscale cluster. The meso-?-scale vortex is the main influence system of this heavy rainfall. The middle and low levels of the troposphere over the heavy rainfall areas produced fast gravity wave. At the same time, the distribution of vertical wind had the characteristic of alternated up and down directions. The gravity wave may be the mechanism triggering this heavy rainfall. The PV sliding along the entropy isoline and the slope vortex development may be the main cause of development of the meso-?-scale vortex. Furthermore, the specific topographty in the Northwest of Human played an important role in the formation and development of this heavy rainfall.更多还原